Cylinder construction for hydraulic apparatus



Oct. 30, 1962 w. A. RAY El'AL 3,061,695

CYLINDER CONSTRUCTION FOR HYDRAULIC APPARATUS Filed Feb. 27, 1959 2 Sheets-Sheet 1 MAI/9M 19.11%

54 P0 m EflA/K B0 HEDGE-E V INVENTORS. 4 5a 55 $9 2 I 4 21 1 BY Z d 3%,

Oct. 30, 1962 w. A. RAY ET AL 3,061,695

CYLINDER CONSTRUCTION FOR HYDRAULIC APPARATUS Filed Feb. 27, 1959 2 Sheets-Sheet 2 Mun/w H. BAY Iq/we B. HEDGEE IN V EN TORS Byzww I TTOEA/EY S.

United States Patent Ofifice 3,061,695 Patented Oct. 30, 1962 3,061,695 CYLINDER CONSTRUCTION FOR HYDRAULIC APPARATUS William A. Ray, North Hollywood, and Frank R. Hedger,

Glendale, Calif., assignors to General Controls Co.,

Glendale, Calif., a corporation of California Filed Feb. 27, 1959, Ser. No. 796,145 4 Claims. (Cl. 20082) This invention relates to hydraulic apparatus utilizing a cylinder and a piston movable by fluid pressure. The piston in turn may be caused to operate an actuator connected to a load, such as a valve closure.

The arrangement is usually such that an electric motor driven pump may be actuated in response to a condition, such as temperature or pressure. Fluid under pressure supplied through the pump outlet then causes the piston to move in one direction in opposition to a spring. When the piston reaches its end position, it operates a switch to deenergize the motor. When it is required to return the piston to its initial position by aid of spring pressure, a relief valve is opened, and the cylinder discharges into a reservoir through the relief valve.

It is one of the objects of this invention to improve in general, apparatus of this character.

In some prior forms of hydraulic actuators, a frame is provided which may be supported on a valve body. The frame serves to support a cylinder in which the actuating piston is accommodated. The motor, pump and the body of oil or other liquid used by the pump is enclosed in a container mounted on the frame. A housing for electrical connections, auxiliary switches, etc. is also carried by the frame. Usually the cylinder is made as a separate piece, as of steel tubing or iron, and held in place in the frame by aid of a clamping device utilizing bolts.

It is another object of this invention to make it possible to simplify the combination of the frame and cylinder.

It is still another object of this invention to ensure against the egress of oil to the exterior of the frame, in a simple and effective manner.

This invention possesses many other advantages, and has other objects which may be made more clearly apparent from a consideration of one embodiment of the invention. For this purpose, there is shown a form in the drawings accompanying and forming a part of the present specification. This form will now be described in detail, illustrating the general principles of the invention; but it is to be understood that this detailed description is not to be taken in a limiting sense, since the scope of this invention is best defined by the appended claims.

Referring to the drawings:

FIGURE 1 is an elevation of an apparatus incorporating the invention;

FIG. 2 is an enlarged longitudinal sectional view of the apparatus;

FIG. 3 is a sectional view, taken along a plane corresponding to line 3-3 of FIG. 2; and

FIG. 4 is a sectional view, taken along a plane corresponding to line 44 of FIG. 3.

In the present instance, a hydraulic actuator mechanism 1 (FIG. 1) is indicated as mounted on top of a valve 2 for operating the valve. This valve 2 may be a fluid fuel valve having a closure operated by the mechanism 1 in response to pressure or temperature conditions.

The operating mechanism includes an actuator 3 (FIGS. 2 and 4) which is connected to a valve control device for valve 2, such as a valve closure. This actuator 3 is carried at the end of a piston rod 4 operated in a manner to be hereinafter described. A disk-like structure 5 is interposed between the actuator '3 and the stem 4 for operating auxiliary mechanism, such as an indicator or electrical circuit controllers.

The main support for the hydraulic mechanism 1 is formed by a frame 6 that may be readily fabricated by a die casting process, utilizing metal such as an aluminum alloy. Integrally formed as a part of the frame is a depending element 7 having two sides, and adapted to be bolted or otherwise attached to the top of the valve 2.

The frame 6, as shown most clearly in FIG. 3, has walls 8 and 9 forming a space accommodating between them a generally circular wall 10 integrally cast with the frame 6. The wall 10 is joined to the opposite walls 8 and 9 by the aid of four lugs, the bottom ones 11 and 12 of which are shown in FIG. 3. Corresponding upper lugs 13 are provided, one of which is indicated in FIG. 4.

An upwardly tapered recess 14 is defined by the interior surface of the wall 10. This taper is conveniently formed by a core, the withdrawal of which from the casting is facilitated by the tapered configuration of the recess 14.

The recess 14 has a bottom surface 15 (FIG. 2) which is apertured to accommodate the piston rod 4.

Urged against this surface 15 is the lower edge of a cylinder shell 16. This shell is preferably made of steel tubing, within which moves a piston structure 17.

In order to urge this shell 16 downwardly, use is made of a cap 18. This cap 18 has a flange 19 externally threaded for cooperation with internal threads 20 formed in an enlarged aperture forming the upper portion of the recess 14. Between this threaded aperture and recess there is an enlarged cylindrical bore portion 21. An O-ring 22 carried in a groove in the periphery of the cap 18 engages this bore, for sealing off the cylinder.

The cap may be appropriately provided with means for facilitating the application of a spanner wrench to turn it down in the threads 20.

A cover plate or nameplate 23 of thin metal extends above the cap 18.

The piston structure 17 includes the piston proper 24 into which is threaded the upper threaded end 25 of the piston rod 4. Appropriate provisions are made to seal the piston in the shell 16. For this purpose, an O-ring 26 is located in a groove formed in the periphery of the piston 24 and a pair of Teflon rings 27 extend on either side of the O-ring 26. Similarly, an O-ring 28 extends around the threaded portion 25.

The piston 24 is resiliently urged downwardly against the surface 15 by a compression spring 29 which is held in compression by the lower surface of the cap 18. The piston rod 4 extends through packing material, including two sections 30 and a third section 31. Section 31 is axially spaced apart from sections 30. All three sections are urged into a bore 32 concentric with the shell 16. In order to maintain the sections 30 axially spaced from the section 3-1, use is made of a washer 33 having ridges to provide radial ports from rod 4 to the bore 32.

In order to urge the piston 24 upwardly against the force of the spring 29, use is made of a pump structure located in a sealed casing 34. The casing serves as a reservoir for the hydraulic fluid and it also encloses an electric motor, the pump, and a relief valve for the pump. When the pump is operated by the motor, oil or other hydraulic fluid under pressure is delivered through a port 35 leading to an annular space 36 below the piston 24. Oil from above the piston structure is urged outwardly through a slot 37 formed in the lower side of the cup 18, to the space between the shell 16 and the recess 14. Thence the oil can pass into the casing 34 by connections to be hereinafter described.

When the rod 4 is moved in this manner to its extreme upper position, provisions are made for deenergizing the sparesa motor in the sealed casing 34, while maintaining the oil under pressure underneath the piston 24. This stops the upward motion and maintains the position of the piston structure 17. When it is desired to return the actuator 3 to its lowermost position, as shown in FIG. 2, the relief valve in casing 34 is opened, and oil is forced through the port 35 back into the casing 34. This mode of operation is now well-known; therefore further recital of details of such hydraulic actuators is unnecessary.

In this process some oil may leak past the packing section 3 1 and into the annular space between the sections 30 and the section 31. This is apt to occur since the space beneath piston structure 17 is subjected to fluid pressure whether the piston is moving upwardly or downwardly. The oil leakage past the packing section 31 is returned to the exterior of the shell 16 via a port 38 to a slot 39 formed in the wall of the recess 14 (see also FIG. 3). By aid of the structure thus far described, it is apparent that any leakage of liquid from the shell 16 outwardly at either its bottom or top edges will simply return the oil or other liquid to the space defined by the tapered recess 14, and thence to the casing 34.

The casing 34 is supported on the right-hand side of the frame 6. Thus the casing 34 has a sealing metal covering plate 40 from which extend four projections 41 having internally threaded apertures. Engaging these apertures are the cap screws 42 which pass through lugs 11, 12 and 13. These lugs may have counterbores such as 43 for the accommodation of the projections 41.

The screws 42 urge the sheet metal covering 40 against the end surfaces of a pair of bosses 44 and 45 (FIGS. 2 and 3.) These bosses have enlarged counterbores accommodating the enlarged cylindrical heads 46 of conduits leading into and out of the casing 34. The lower boss 45 is in communication with the port 35 and the upper boss 44 is in communication with a similar port 47. This port 47 communicates with the space between shell 16 and recess 14, whereby upon movement of the piston structure 17 in either direction, liquid flows from or into shell 16 via port 47 and slot 37.

In order to provide a tight seal between the heads 46 and frame 6, Orings 48 and 49 are provided in grooves in the bosses 44 and 45.

Another casing 50 is appropriately supported on the left-hand side of the frame member 6. This casing 50 may be provided with a wall 51 upon which are supported one or more circuit controllers 52, 53 (see FIG. 3). Each of the circuit controllers has a plunger, such as 54 (FIG. 2) operated by a lever structure having an arm 55. This arm 55 has extensions 56 and 56' passing through narrow apertures 58 in the wall 51, for operating auxilary switches in the casing 50 if desired. The lower inner edge of the aperture 58 serves as a focal point for the lever 55. In order to urge the lever 55 toward this edge, the lever 55 is urged inwardly and downwardly by the aid of a tension spring 57, anchored to the lever 55 and to wall 51 by the aid of appropriate apertures formed in the wall 51.

In order to operate the lever 55 and thereby the circuit controllers 52 and 53, use is made of a push rod 59 which is guided by the aid of a mounting bolt 60 passing through the lower wall of the frame 6. Appropriate means such as a pin 61 may be provided for limiting downward movement of the push rod 59.

When the piston rod 4 is moved upwardly to the limit of its motion, the disk-like structure 5 moves into engagement with the lower end of the rod 59 and moves it upwardly to operate the circuit controllers 52 and 53. One of these circuit controllers is utilized for disconnecting the electric motor operating the pump in the casing 34.

The inventors claim:

1. In apparatus of the character described: a frame having an inwardly tapered recess, said recess having an apertured bottom surface; a cylinder shell resting on said bottom surface; there being an increasing clearance between the shell and the recess toward the top of the recess; means urging the shell against said bottom surface; said frame having ports, one to the bottom surface, and one adjacent the top of the tapered recess; and a piston in said shell; said frame having provisions for connecting the bottom port to the interior of the shell below the piston; said frame also having provisions for connecting the top port, via the clearance between the shell and the wall of the recess, to the top of the shell and to the space above the piston.

2. In apparatus of the character described: a frame having an inwardly tapered recess, said recess having an apertured bottom surface; a cylinder shell resting on said bottom surface; there being an increasing clearance between the shell and the recess toward the top of the recess; means urging the shell against said bottom surface; said frame having ports, one to the bottom surface, and one adjacent the top of the tapered recess; a piston in said shell; a piston rod extending through the aperture in the bottom surface; packing in the frame around the rod, said packing being in two sections; and means forming a passage from between the sections to the port near the top of the recess.

3. The combination as set forth in claim 2, in which the passage forming means includes a slot in the side of the tapered recess.

4. In apparatus of the character described: a frame having an inwardly tapered recess, said recess having an apertured bottom surface; a wall of said frame defining a space exterior of said recess; a cylinder shell resting on said bottom surface; the upper portion of said recess being enlarged and internally threaded; a cap threadedly engaging said internally threaded portion and having a surface urging said shell against said bottom surface; a piston in the shell; a stem for the piston extending through the aperture in the bottom surface; one or more switches supported by the frame in said space, each having an operating plunger; a lever for moving the plunger or plungers; said lever being mounted by aid of said wall; and a push rod guided by the frame and operated by movement of the stem toward the top of the recess, for urging the lever to operate the plunger or plungers.

References Cited in the file of this patent UNITED STATES PATENTS 1,068,945 Taylor July 29, 1913 1,141,158 Turner June 1, 1915 2,650,275 Doutt Aug. 25, 1953 2,656,820 Becker Oct. 27, 1953 2,695,009 Sloan Nov. 23, 1954 2,736,778 Buchanan Feb. 28, 1956 2,860,203 Haessler Nov. 11, 1958 

